Integrated round with combustible cartridge

ABSTRACT

An integrated round comprising a projectile threaded at one end thereof, an integral combustible carriage and means for threadably mounting the projectile onto the combustible cartridge after the cartridge has been loaded with primers and propellants.

United States Patent Larson 14 1 Apr. 25, 1972 [541 INTEGRATED ROUNDWITH 2,920,563 1/1960 De Caro ..102/3s COMBUSTIBLE CARTRIDGE 3,288,06611/1966 Stadler et a] ..102/38 [72] Inventor: Willard D. Larson,Midland, Mich. FOREIGN PATENTS OR APPLICATIONS 1 u Dow CorningCorporation. Midland, Mich- 24,289 1894 Great Britain ..102/38 [22]Filed: A 17, 1970 1,527,326 1968 France ..1o2/43 P UNITED STATES PATENTS819,634 5/l906 Brubaker ..lO2/38 8/1908 Harris ..l02/38 Appl. No; 29,572

U.S. c1. ..'.....1o2 /3s, 102/1510. 1, 102/43 1m. c1, ..;-..'...'.'F42b5/18, F42b 9/16 102/38, 40,- 43, 43 P, 43 1-",

Field of Search References Cited Primary ExaminerRobert F. StahlAttorney-Robert F. Fleming, Jr., Lawrence R. Hobey, Harry D. Dingman andHoward W. Hermann 1 571 ABSTRACT An integrated round comprising aprojectile threaded at one end thereof, an integral combustible carriageand means for threadably mounting the projectile onto the combustiblecartridge after the cartridge has been loaded with primers andpropellants.

10 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION The presentinvention relates to the field of ammunition, and more particularly, toa round of ammunition including a combustible cartridge.

Combustible cartridges can be made that weigh less and occupy lessvolume than the conventional metal cartridge. Further, combustiblecartridges obviate the problems of spent metal cartridges and the needfor ejecting them and provide a reduction in the unit cost of ammunitionand in logistic storage and supply costs, due to the reduction in weightand volume of ammunition incorporating them.

Because the physical properties of a combustible cartridge are differentfrom the physical properties of a conventional metal cartridge, it isnot generally possible to attach a warhead or projectile to thecombustible cartridge in the same manner that such a warhead orprojectile can be attached to the conventional metal cartridge. Forexample, the conventional metal cartridge has almost universally beenmade of brass and a projectile has been secured in the open end of thecartridge by radially crimping or indenting the cartridge at the openend so that it tightly encompassed the base of the projectile. Thismethod of attachment cannot be used with most combustible cartridges,since the material from which such cartridges are made cannot readily becrimped.

Another method of attaching a warhead or projectile to a conventionalmetal cartridge is provided by inserting into the open end of acartridge case a threaded bushing which is removably engaged by matingthreads about the base of the projectile. Such a bushing is bonded tothe interior surface of the case by any suitable means, such as solder.This method of attaching a projectile to a conventional cartridge casehas also been found to be unsatisfactory for use with a combustiblecartridge.

A method that is known in the ammunition art for assembling a projectileto a combustible cartridge requires the combustible cartridge to be madein two parts. That is, a threaded portion on the base of a projectile isinserted into one end of an open tube of the combustible material and isattached to that tube by a retaining nut that is threaded onto thethreads of the projectile from the opposite end of the tube ofcombustible material. Then, the propellant and primers are loaded intothe tube of combustible material and a U-shaped base of combustiblematerial is adhered to that tube.

This method is undesirable because it requires two separatemanufacturing machines to produce the two parts of the cartridge, itrequires the warhead to be attached to the cartridge before the primersand propellant are loaded into the cartridge, a double thickness of thecartridge separated by a layer of glue is formed at the base of thecartridge and the seam formed at the base of the cartridge is verydifficult to make liquid-or watertight.

SUMMARY OF THE INVENTION The primary object of the present invention,therefore, is to provide an improved integrated round that will be freefrom the aforementioned'and other disadvantages of prior devices of thistype. 1

More particularly, it is an object of the present invention to providean integrated round having an unitary combustible cartridge to which awarhead or projectile can be attached after the propellants and primersare loaded into that car In accordance with these and other objects,there is provided by the present invention an integrated round having anintegral combustible cartridge and means for threadably mounting aprojectile or warhead thereon after the propellants and primers areloaded into that cartridge.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and many more attendantadvantages will become obvious to those skilled in the art by readingthe following detailed description in connection with the accompanyingdrawings wherein:

FIG. 1 is an exploded side view, partially in cross-section, of theintegrated round of the present invention;

FIG. 2 is a top view of the unitary combustible cartridge of the roundshown in FIG. 1; and

FIG. 3 is a top view of the threaded collar shown inserted into theunitary combustible cartridge of the round in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingswherein like reference numerals designate like or corresponding partsthroughout the figures thereof, there is shown in FIG. 1, an integratedround of ammunition 11. Although the round 11 is shown in an explodedview in FIG. 1, it is to be understood that the present inventioncontemplates an integrated round, comprising a unitary combustiblecartridge 14, a threaded collar 17, a coupling ring 21 and a projectile25.

The unitary combustible cartridge 14 has an axial cavity 31 therein andan orifice 33 at one end thereof. The orifice 33 provides an openinginto the cavity 31 of the unitary combustible cartridge. Preferably, thecombustible cartridge 14 is of substantially uniform thickness and canbe shaped to optimize combustion of the cartridge and to accommodatevarious sizes of propellant and primer charges. The combustiblecartridge 14 can be a molded propellant comprising granules ofpropellant bonded in a molded mass by a low-nitrogen nitro-cellulosebinder. However, the cartridge 14 can be made from any other suitablecombustible material, if desired.

The integral collar 17 has a neck portion 35 and a shoulder portion 37.The shoulder portion 37 is inserted into the cavity 31 of the cartridge14 through the orifice 33. Preferably, the neck 35 of the collar 17 isexternally threaded and the shoulder portion 37 is complementary to andcoextensive with the inner surface area of the cartridge 14 surroundingthe orifice 33. The collar 17 does not need to be combustible and ispreferably made of brass or steel.

Preferably, the orifice 33 of the cartridge 14 and the shoulder 37 ofthe collar 17 are substantially annular and the outer diameter of theshoulder 37 is greater than the diameter of the orifice 33. If theshoulder portion 37 of the collar 17 is made of a flexible material, theshoulder portion 37 can be inserted through the orifice 33 by merelyflexing or bending the shoulder to a diameter that is less than thediameter of the orifice 33. If desired, a slit can be provided in theshoulder 37 to make it more flexible; However, when the shoulder 37 ismade from an inflexible material, the orifice 33 and the collar 17 canbe modified advantageously as shown in FIGS. 2 and 3.

. That is, the configuration of the orifice 33 can be modified toprovide an opening into the cavity 31 having a diameter that is greaterthan the outer diameter of the shoulder 37 on the collar 17. Such anopening can be provided by the means of at least one or, preferably, twoaxial slots 41 opening into the orifice 33 in the wall of the cartridge14 surrounding the orifice. Additionally, the outer diameter of theshoulder 37 can be reduced at some portion thereon by cutting off ortrun eating the shoulder 37 at one or, preferably, two locations orsides of the collar, as illustrated at 43 in FIG. 3. In some instances,only the notch 41 or the truncation 43 will be necessary to enable thecollar 17 to be inserted through the orifice 33.

It will be obvious that when the orifice 33 and/or the collar 17 hasbeen modified as shown in FIGS. 2 and 3, the collar 17 can be freelyinserted into the cavity 31 through the orifice 33 when the collar 17 isplaced on its side.

The coupling ring 21 has threads that are complementary to the threadson the neck 35 of the collar 17 and has an endwall that is complementaryto the outer surface of the cartridge 14 that surrounds the orifice 33.Preferably, the coupling ring 21 is made from brass or steel and iscoextensive with the outer surface of the cartridge 14 that surroundsthe orifice 33.

The coupling ring 21 is threaded onto the neck 35 of the collar 17 afterthe shoulder 37 has been inserted into the cavity 31. When the couplingring 21 has been fully threaded onto the neck 35, a tight compressionfitting can be obtained between the endwall of the coupling ring 21, theinner and outer surfaces of the cartridge 14 surrounding the orifice 33and the shoulder 37 of the collar 17. Preferably, a sealer can beapplied to the complementary surfaces of the endwall on the couplingring 21 and the outer surface of the cartridge 14 surrounding theorifice 33 to seal the seam between those surfaces. Although that sealercan be applied either before or after the surfaces are brought intocontact, it is preferred to apply that sealer before the coupling ring21 is threaded onto the collar 17.

Suitable primers and/or propellants can be loaded through the orifice 33of the cartridge 14 after the coupling ring 21 has been attached to thecartridge. In some instances, after the primers and propellants havebeen loaded into the cartridge, it may be desirable to store thecartridge without attaching a projectile or warhead to it. Accordingly,if desired, the coupling ring 21 can have a cover or diaphragm 45, asshown in FIG. 1, attached or otherwise placed across its aperture toprotect the contents of the cartridge 14 from its environment. Althoughthe primers and propellants are depicted as loose granular materialswithin the cavity 31, as shown in FIG. 1, it is to be understood thatthe primers and propellants can be in any suitable form, such as in asack or as molded solid charges.

The warhead or projectile 25 has threads at its base which arecomplementary to the threads of the coupling ring 21. Although thecoupling ring 21 is shown in FIG. 1 as having one uniform internalthread through its entire thickness, if desired, the coupling ring 21can have one set of threads complementary to the threads on the collar17 and another set of threads complementary to the threads of the baseof the projectile 25.

When the projectile 25 is threaded into the coupling ring 21, theintegrated round of ammunition 11 is complete. However, the projectile25 can be stored separately from the remainder of the round 11 andassembled at the time it is to be used. Further, once the projectile 25has been attached to the combustible cartridge 14, it can be readilyremoved, if desired, for the purpose of inspecting the propellants andprimers in the cartridge 14, and then readily reassembled.

Having now described the invention in specific detail and exemPlifiedthe manner in which it may be carried into practice, it will be readilyapparent to those skilled in the art that innumerable variations,applications, modifications and extensions of the basic principles.involved may be made without departing from its sphere or scope.

That which is claimed is:

1. An integrated round comprising in combination:

a unitary combustible cartridge of substantially uniform thicknesshaving an axial cavity therein and an orifice at one end thereof,

propellants contained in said cavity within said cartridge,

a threaded collar having an integral neck and shoulder portion, whichshoulder portion is inserted into said cavity through said orifice andis substantially complementary to the inner surface area of saidcartridge surrounding said orifice,

a coupling ring having threads complementary to said threads on saidcollar and having an endwall that is substantially complementary to theouter surface area of said cartridge surrounding said orifice, whichcoupling ring is threaded onto said neck of said collar, and

a pro ectile having at one end thereof threads complementary to threadsof said coupling ring, which projectile is threaded into said couplingring.

2. The round as defined in claim 1, wherein said threads on said collarare external threads on the neck of said collar, said threads on saidcoupling ring are internal threads, and said threads on said projectileare external threads.

3. The round as defined in claim 1 and further comprising a sealant incontact with said endwall of said coupling ring and said outer surfacearea of said cartridge surrounding said orifice.

4. The round as defined in claim 1, and further comprising in the wallof said cartridge surrounding said orifice, an axial slot opening intosaid orifice.

5. The round as defined in claim 4, wherein said cartridge iscylindrical, said orifice is circular and the rim of said shoulder onsaid collar defines a circle truncated on two sides.

6. The round as defined in claim 1, and further comprising a diaphragmacross the aperature of said coupling ring.

7. The round as defined in claim 1, wherein said shoulder on said collaris substantially coextensive with the inner surface of said cartridgesurrounding said orifice and said endwall on said coupling ring issubstantially coextensive with the outer surface of said cartridgesurrounding said orifice.

8. The round as defined in claim 1 and further comprising primerscontained in said cavity within said cartridge.

9. A method of forming an integrated round comprising:

providing a unitary combustible cartridge of substantially uniformthickness having an axial cavity therein and an orifice at one endthereof,

inserting a threaded collar having an integral neck and shoulder portioninto said cavity through said orifice and causing said shoulder portionto remain in juxtaposition with the inner surface area of said cartridgesurrounding said orifice and said neck of said collar to extend out ofsaid cartridge through said orifice,

threading a coupling ring having threads complementary to said threadson said collar onto said collar until the endwall of said coupling ringis in juxtaposition with the outer surface area of said cartridgesurrounding said orifice,

loading primers and propellants into said cavity of said cartridge, and

threading onto said coupling ring a projectile having at one end thereofthreads complementary to threads on said coupling ring.

10. The method as defined in claim 9 and further comprising the step ofapplying a sealant material to the outer area of said cartridgesurrounding said orifice.

1. An integrated round comprising in combination: a unitary combustiblecartridge of substantially uniform thickness having an axial cavitytherein and an orifice at one end thereof, propellants contained in saidcavity within said cartridge, a threaded collar having an integral neckand shoulder portion, which shoulder portion is inserted into saidcavity through said orifice and is substantially complementary to theinner surface area of said cartridge surrounding said orifice, acoupling ring having threads complementary to said threads on saidcollar and having an endwall that is substantially complementary to theouter surface area of said cartridge surrounding said orifice, whichcoupling ring is threaded onto said neck of said collar, and aprojectile having at one end thereof threads complementary to threads ofsaid coupling ring, which projectile is threaded into said couplingring.
 2. The round as defined in claim 1, wherein said threads on saidcollar are external threads on the neck of said collar, said threads onsaid coupling ring are internal threads, and said threads on saidprojectile are external threads.
 3. The round as defined in claim 1 andfurther comprising a sealant in contact with said endwall of saidcoupling ring and said outer surface area of said cartridge surroundingsaid orifice.
 4. The round as defined in claim 1, and further comprisingin the wall of said cartridge surrounding said orifice, an axial slotopening into said orifice.
 5. The round as defined in claim 4, whereinsaid cartridge is cylindrical, said orifice is circular and the rim ofsaid shoulder on said collar defines a circle truncated on two sides. 6.The round as defined in claim 1, and further comprising a diaphragmacross the aperature of said coupling ring.
 7. The round as defined inclaim 1, wherein said shoulder on said collar is substantiallycoextensive with the inner surface of said cartridge surrounding saidorifice and said endwall on said coupling ring is substantiallycoextensive with the outer surface of said cartridge surrounding saidorifice.
 8. The round as defined in claim 1 and further comprisingprimers contained in said cavity within said cartridge.
 9. A method offorming an integrated round comprising: providing a unitary combustiblecartridge of substantially uniform thickness having an axial cavitytherein and an orifice at one end thereof, inserting a threaded collarhaving an integral neck and shoulder portion into said cavity throughsaid orifice and causing said shoulder portion to remain injuxtaposition with the inner surface area of said cartridge surroundingsaid orifice and said neck of said collar to extend out of saidcartridge through said orifice, threading a coupling ring having threadscomplementary to said threads on said collar onto said collar until theendwall of said coupling ring is in juxtaposition with the outer surfacearea of said cartridge surrounding said orifice, loading primers andpropellants into said cavity of said cartridge, and threading onto saidcoupling ring a projectile having at one end thereof threadscomplementary to threads on said coupling ring.
 10. The method asdefined in claim 9 and further comprising the step of applying a sealantmaterial to the outer area of said cartridge surrounding said orifice.